It is known in the field of high frequency signal transmission that signal lines need to be electrically isolated from adjacent signal lines and ambient electromagnetic energy in order to prevent degradation to the transmitted signal. This is typically accomplished by applying one or more layers of shielding, such as braided metal wire or tape, or one or more layers of metal coated polymer tape. Each additional conductive layer increases the shielding effectiveness of the cable.
Problems occurring terminating multiple shields to ground or in commonly grounding all layers of shielding. Some cables use a metal coated polymer tape wrapped over drain wire which are electrically connected to ground to simplify the termination process. This type of construction can be used where comprises in shielding effectiveness are acceptable. For improved shielding, a metalized tape comprsing of two metal layers sandwiching a non-conductive polymer layer can be used. When two or more layers of such a tape are used in conjunction with one or more drain wires, the effective shielding can be similar to that of a braided wire shield. Multiple layers of such shielding tape however make a cable relatively inflexible. Additionally, the use of multiple metalized tapes will complicate to the termination process when the shield tapes need to be removed.